Wire staple handling apparatus



July 28', 1959 T. M. WRIGHT WIRE STAPLE HANDLING APPARATUS 9Sheets-Sheet 1 Filed Aug. 14. 1956 ATTORNEY i l N M July 28, 1959 T. M.WRIGHT WIRE STAPLE HANDLING APPARATUS 9 Sheets-Sheet 2 Filed Aug. 14.1956 6 5 I 2, \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\A m 2 4 4% 1 WM I y mi mx 0 Q "a 4 a. 1 7 6 0 A :WV .11 A fl m l e a I 1 y 0 A A R T .A... v u wc. fl i fl T. M. WRIGHT WIRE STAPLE HANDLING APPARATUS July 28, 1959Filed Aug. 14. 1956 9 Sheets-Sheet 5 T. M. WRIGHT WIRE STAPLE HANDLINGAPPARATUS July 28, 1959 9 Sheets-Sheet 4 Filed Aug. 14. 1956 p a g INVEN TOR. Headare M Mzfif AZTOKMY.

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ATTORNEY T. M. WRIGHT WIRE STAPLE HANDLING APPARATUS July 28, 1959 9Sheets-Sheet '7 Filed Aug.- 14. 1956 ATTOFACEY 1959 T. M. WRIGHT I2,896,214 WIRE STAPLE HANDLING APPARATUS Filed Aug. 14. 1956 9Sheets-Sheet. a

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YZam'omM M15152 AZYURIVEX July 28, 1959 T. M. \INRIGHT 2,896,214

WIRE STAPLE HANDLING APPARATUS IN V EN TOR.

AI'IURIVEX nite This invention relates to wire staple handlingapparatus, and more particularly to apparatus for forming and securingwire staples to the edge of a sheet of material which may, for example,be the edge of a paper box.

Wire staples of the general type to which this invention relates areillustrated in US. Patent 1,825,140 issued to K. F. Berthold and in US.Patent 2,138,495 issued to A. J. Lewis. The staple, itself, is in theform of a length of wire bent into a generally U-shaped configurationwith a shoulder formed in each leg of the U.

In the prior art machines, the U-shaped staples are formed in a verticalplane, and the ends of the U are forced through the sheet member towhich the staples are applied adjacent to the edge of the sheet.Thereafter, certain members sweep across the edge of the sheet member tobend and fold the staples over the edge. In these machines, the sheetmember itself must supply the counter force which is applied to thestaple for cooperation with the sweeping members in effecting thefolding of the staple. Thus, the sheet member must be sufiicientlystrong to withstand the strain necessary to supply such bending force.

The primary object of the present invention is to provide an improvedapparatus for forming and applying wire staples to the edge of a sheetmember, which apparatus will be free from the aforementioned difiiculty.

More particularly, it is an object of the present invention to provideimproved wire staple forming and applying apparatus as set forth whereinno strains are imposed upon the sheet member in effecting the seeming ofthe staple thereto.

It is a further object of the present invention to provide improveddrive means for apparatus of the type set forth.

Yet another object of the present invention is to provide an improved,selectively engageable, automatically disengageable clutch which, whileparticularly useful in apparatus of the type set forth, is of wider andmore general usefulness.

In accomplishing these and other objects, there has been provided, inaccordance with the present invention, wire staple forming and applyingapparatus having means for feeding in and cutting off a desired lengthof wire from which a substantially U-shaped staple is formed in ahorizontal plane. The horizontally disposed staple is then moved to abending and applying position where the loop portion of the staple isheld firmly. The ends of the legs are next bent to an angle ofsubstantially 90 with respect to the plane of the body of the staple.The bent legs are fully supported and pushed through the edge of thesheet to which the staple is to be affixed. While the loop portion ofthe staple is held firmly, the leg ends extending through the edge ofthe sheet are bent, first back toward the edge of the sheet, and thenover the edge to wrap around the sides of the loop portion. Theloop'portion of the staple is held firmly throughout the bendingoperation. At no time is the strength of the sheet member relied upon toassist in the bending operation.

The invention itself, both as to its organization and 2 method ofoperation, as well as additional objects" and ad= vantages thereof, willbe understood more readily from the following description, when read inconnection with the accompanying drawings, in which:

Fig. 1 is a perspective view, with one side panel open to show theinterior mechanism, of one form of stapling machine constructed inaccordance with the present invention,

Fig. 2 is a front elevational View, partly in phantom and partly brokenaway, of the apparatus shown in Fig. 1,

Fig. 3 is a sectional view taken along the line 33 of Fig. 2, and viewedin the direction of the appended arrows, i

Fig. 4 is a partial sectional view taken along the line 4--4 of Fig. 3and viewed in the direction of the appended arrows,

Fig. 5 is a perspective view of the staple-forming por tion of theapparatus of Fig. 1,

Fig. 6 is a perspective view of the staple clincher assembly of theapparatus of Fig. 1,

Fig. 7 is a perspective view of the staple holding and leg bendingassembly,

Fig. 8 is a detailed perspective view of the staple holding die of theassembly shown in Fig. 7,

Fig. 9 is a detailed perspective view of the staple-wire cut-elfmechanism,

Fig. 10 is an exploded view of the cams which effect the operation ofthe apparatus of Fig. 1,

Fig. 11 is a pictorial flow diagram illustrating the forming of thestaple and its movement into engagement with the holding die shown inFig. 8,

Figs. 12, 13 and 14 are detailed views, partly broken away and insection, illustrating the progressive steps of bending the legs of thestaple and thendriving the bent legs through the sheet member,

Figs. 15, 16 and 17 are detailed views illustrating the progressivesteps of clinching the staple over the edge of the sheet member,

Fig. 18 is a view showing a completed, clinched staple secured to asheet member,

Fig. 19 is an elevational view of a once-around clutchbrake mechanism inaccordance with the present invention for driving the shaft carrying thecams of Fig. 10, the clutch being shown in the disengaged condition,

Fig. 20 is a view similar to. Fig. 19, but showing the clutch in itsengaged condition,

Fig. 21 is aside view of the clutch, and

Fig. 22 is an enlarged, detail view. showing the wire clampingmechanism.

Referring, now, to the drawing in more detail, there is shown, in Figs.1 to 3, a front mounting panel 2, a; base member 4 and a rear mountingpanel 6. Each of these members is made of suitable metal of sufiicientthickness and strength to support, during operation, the severalelements carried thereby. Extending between the front panel 2 and therear panel 6 at an elevation somewhat above the center, there is a mainbrace and a horizontal mounting bar 8. Also extending between the twopanels 2 and 6, and journalledtherein, is a main camshaft 10;

At the top of the front panel 2 is a bracket 12 which carries a supplyspool'14 of wire 16 from which the staples are to be formed. A guidemember 18' leads the wire from the, spool 14 to a feed tube 20 which, inturn, leads the wire 16 to a wire feed mechanism 21 (Fig. 2

Mounted on the upper half of the front surface of the front panel 2 is astaple holding and leg bending subassembly 22. This subassembly is showninmo're detail in Fig. 7. The subassembly 22 is driven by a. lever 24which is coupled to the subassembly 22 lbyfa connecting link 26. Thelever 24. is pivotally mounted on a' stud 28 carried by a supportingboss 30. The: boss 30 is secured to the rear surface of the front panel2. The lever 24 extends through a suitable opening 32 in the panel 2.,"The to the anvil.

end of the lever 24 opposite from the link 26 is connected, by a secondlink 34, to a cam follower arm 36. The cam follower arm-36 is pivotallycarried bya suitable stud extending from a boss 38. A tension spring 40,coupled between a stud 42 on the lever 24 and an anchor eye 43 in thebase member 4, provides the necessary return force for the resetoperation of the subassembly 22. The subassembly 22 includes two mainmoving members which will be described more fully hereinafter. These twomoving members are'coupled, respectively, to the driving link 26 by apair of connecting links 44 and 46 and a pin 48 which extends throughand couples together the links 44, 46 and 26. Selective operation of thetwo aforementioned moving members is effected through engagement of acam follower extension, which projects rearwardly from'the pin 48, and acam member 50.

Below the subassembly 22, and extending through the front panel 2, is astaple clinching subassembly'52. This subassembly is shown in moredetail in Fig. 6. Some of the moving parts of the subassembly 52 areoperated by a first lever 54 which is shown broken away in Fig. 3. Thelever 54 is pivotally carried by a boss 56 which is, in turn, mounted onthe front panel 2. A link 58 conples the lever 54 to a cam follower arm60. Others of the moving parts of the subassembly 52 are operatedthrough a linkage including a cam follower arm 62, a link 64, a crank 66on a rod 68, and a pair of coupling links 70 and 72. A tension spring74, extending between the crank 66 and an anchor eye 76 on the basemember 4, provides the necessary return force to reset that portion ofthis subassembly which is operated by the last mentioned linkage. Asimilar tension spring 78 is coupled between the follower arm 60 and anoverhead anchor eye 80 and supplies the necessary restoring force forthat portion of the subassembly operated by the lever 54.

Mounted on the side of and supported by the horizontal mounting bar 8 isa staple forming subassembly 82. This subassembly is shown in moredetail in Figs. 4 and 5. The moving parts of the subassembly 82 areoperated by a link 84 coupled to one leg of a bell-crank 86 (see Fig.4). The bell-crank 86 is supported on a boss 88 mounted on the mountingbar 8 and is driven through a link 90 coupled to a cam follower arm 92(see Figs. 2 and 3). The cam follower arm 92 is reset to its normal orrest position by a pair of springs 93 which connect it to a pair offixed pins on the rear panel 6.

Associated with the staple forming subassembly 82 is a wire holdingfinger 94 (see Figs. 2, 3 and 4). This finger 94 holds a severed lengthof wire in position to be formed into a staple by the staple formingmechanism. The finger 94 is moved into and out of operating position bya slide block 96 which is driven by a link 98 coupled to a crank lever100. The crank lever is, in turn, coupled by a link 102 to a followerarm 104 (best seen in Fig. 1). slide block 96 is guided in its motion bysliding engagement with a guide rod 106.

constituting an intermediate mechanism, in that it is physically a partof the clinching subassembly 52 but operates in association with thestaple forming subassembly 82, is a staple forming anvil 108 (see Figs.3, 4, 6 and 11). The anvil 108 is arranged for slight vertical movementfor a purpose presently to be set forth. To accomplish this, the anvil108 is provided with a depending leg 110 which is provided with a recess112. A stud 114 carried by a lever 116 is nested within the recess 112.The lever 116 is pivotally mounted on a boss 118 and is coupled by alink120 to a cam follower arm'122. Operation of this linkage provides aslight amount of vertical motion As was previously mentioned, the wire16 is fed. through the feed tube 20 to a. wire feedmechanism21. -Thismechanism is shown in Fig. 2. A cam follower arm 124 carries a large'sector gear 126. A biasing spring 128 The gear 126 and its associatedmechanism. The sector gear 126 is positioned to engage a first spur gear130 which, in turn, engages a second spur gear 132. The spur gears 130and 132 respectively carry smooth wheels 134 and 136 for rotationtherewith. The diameter of the wheels 13 4, 136 is substantially equalto or slightly less than pitch diameter of the associated gears. Thelowermost gear 130 is mounted on a fixed stud 138 for rotation about afixed axis. The other gear 132, however, is mounted for rotation about astud 140 the axis of which may be slightly shifted. The stud 140 is aneccentrically disposed extension from the end of a larger stud 142. Theaxis of rotation of this larger stud is fixed. A crank member 144 iskeyed to impart a slight rotation to the stud 142, thereby slightlyshifting the axis of the smaller stud 140.

The crank 144 is normally biased in a counterclockwise direction (asviewed in Fig. 2) by a spring 146. However, the crank 144 is constrainedin a direction to oppose the biasing force by a pivoted plate member 148having a lip 150 (see Fig. 9). The lip 150 carries an adjustable screwstop pin 152 which engages a tang 154 on the crank 144. The plate member148 is pivotable about the axis of the stud 142 under the control of alink 156. The link 156 is connected to be driven by a cam follower arm158 which is biased clockwise (as viewed in Fig. 2) by a spring 159.

Positioned above the lip 150 of the plate member 148 is a wire clampactuating member 160. The member 160 also includes a tang which extendsover the lip 150 and carries an adjustable screw stop pin 161 the lowerend of which cooperates with the upper surface of the lip 150. Themember 160 is biased by a spring 163 in a counterclockwise direction (asviewed in Fig. 22) about an axis defined by a pin 162. The rotationalmotion of the member 160, under the influence of the biasing spring 163,is limited by the engagement of the pin 161 with the upper surface ofthe lip 150. However, the pin 162, which determines the axis of rotationof the member 160, is keyed to rotate with the member 160. This pin 162has an extension which has a flattened face 165 on the lower side. Oneside of the flattened face of the pin 162 engages a wire clamping rod164. This rod 164 extends through a suitable opening in the base of thewire feed subassembly to rest upon the upper surface of the wire 16. Abacking block 166 is positioned to engage the opposite side of the wirefrom the rod 164. When the member 160 is allowed to be rotated slightlyin a counterclockwise direction (as viewed in Figs. 2 and 22), theflattened face 165 of the pin 162 forces the rod 164 downwardly to clampthe wire 16 between the lower end of the rod 164 and the backing block166.

Whenever the follower arm 158 is operated by its associated cam 168 (seeFig. 10), the plate member 148 is pushed upward by the link 156. Aslight amount of play or lost motion is included in the movement of thelip 150 between the two tangs 154 and 160. The initial upward motion ofthe pin allows the crank 144 to rotate slightly under the influence ofthe spring 146. This causes a shift in the axis of the upper gear 132and, hence, of the associated wheel 136. The direction of the shift inthe axis of the wheel 136 is such as to bring the wheel 136 closer tothe other wheel 134. The magnitude of the shift in the axis is limitedby the length of the gear teeth on the two gears 130 and 132. The gearteeth never become completely disengaged. When the two wheels areshifted provides the necessary restoring force for h sector 7 intocloser proximity, the wire is clamped between them.

Further upward movement of the lip 150 brings it into engagement withthe lower end of the screw pin 161 to produce a clockwise rotation ofthe clamp actuating member 160 (as seen in Figs. 2 and 22) against theforce of its biasing spring. This clockwise rotation of the member 160releases the pressure on the rod 164, thereby unclamping the wire atthat point. I

In the condition thus established, the arm 124 carrying the sector gear126 may be actuated by its associated cam 170 (Fig. Operation of thisarm 124 causes the two spur gears 130, 132 with their associated wheels134, 136 to be rotated. Since the Wire 16 is pinched between the twowheels 134, 136, a rotation of the wheels causes the wire to beadvanced. The excursion of the sector gear 126 and the diameters of thetwo wheels 134, 136 measures out a predetermined length of wire.

After the measured length of wire 16 has been advanced, the cam 168reaches a contour, with respect to the cam follower 172 on the arm 158,which first allows the plate 148 to reestablish a clamping of the wirebetween the rod 164 and the backing block 166, and then to disengage thewheels 134 and 136 from the wire. However, simultaneously therewith, thearm 158 operates to also cause the measured length of wire to be cutoff. For this purpose, a wire cutting knife 174 (Fig. 9) is slidinglymounted in a guide block 176. The knife 174 is driven forward to shearthe wire, by actuation of a bell-crank driver member 178. The bell-crankdriver member 178 is coupled to the arm 158 by a link 180. This may bemost clearly seen by reference to Fig. 9. A spring 182 applies thenecessary restoring force to the knife.

At the time that the measured length of wire is cut off, that measuredlength is positioned across the staple forming subassembly 82, ready tobe formed into a staple. In describing this operation, particularreference will be made to Figs. 4, 5, 6 and 11.

It Will be remembered that a staple forming anvil 108 was described as apart of the clinching subassembly 52 but designed to be functionally apart of the staple forming subassembly 82. This anvil 108 was describedas I being movable slightly in a vertical direction. This anvil member108 is carried in a base block 183. At the time that the measured lengthof wire is cut off, the anvil 108 is in its uppermost position andprotrudes slightly above the surface of the base block 183. The wirerests on the base block 183 adjacent the end of the anvil 108. Thefinger 94 is moved to its lowermost position and holds the severedlength of wire 16 in. the position just described.

The remainder of the staple forming subassembly includes a mountingbracket 184 by means of which the subassembly is secured to the mountingbar 8. It also includes a pair of side guide blocks 186, a slide member188, and a pair of top guide plates 190. The slide member 188 is coupledto and driven by the link 84, in the manner described above. The forwardend of the slide member 188 is provided with a notch 192 which is shapedcomplementarily to the anvil 108, that shape being the desired contourof the staple to be formed. In this case, the staple 193 will be givensubstantially a U-shaped configuration with a shoulder part way downeach leg of the U. Upon being driven forward by the link 84, the slidemember 188 engages the cut length of wire and bends it around the anvil108. The forward motion of the slide member 188 is continued until thewire is formed firmly between the outer surface of the anvil 108 and thecomplementary curve of the notch 192. The base of the notch is providedwith a further recess 194 to accommodate the end of the finger 94 whichcontinues to hold the wire until the staple 193 is completely formed.

When the staple 193 has been completely formed, as just described, thefinger 94 is retracted by operation of its operating cam 1196. incooperation-withits associated follower arm 104, At the same time, theanvil 108 is. retracted or lowered below the surface of the base block183,by the cooperative action of the follower am 122 with itsassociated. cam 198. During the time that the finger '94. is beingraised and the anvil 108 is being lowered, thecam follower arm 92encounters a' momentary dwell on the surface of its driving cam 200.After the finger 94 and the anvil 108 have been retracted, the earn 200-again rises, thereby continuing the forward motion of the slide member188. The slide member 188 then carries the newly formed staple 193forward to the staple holding and leg bending subassembly 22.

Reference is now made to Figs. 7, 8 and 12 to 14. The subassembly 22includes a staple holding block 202 (shown most clearly in Fig. 8)secured to a rear slide plate 204. This constitutes one of the twormainmoving members to which previous reference was made. The rear slideplate 204 is coupled, through a stud 206, to the previously mentionedlink 44. The rear slide plate 204 is held on a submounting plate 208 bya pair of side guide bars 210. A pair of spacer bars 212 are positionedin front of the bars 210 and are, in turn, overlaid by a pair of frontguide bars 214. A front slide plate 216 is positioned for operation inthe recess defined by the two front guide bars 214.

Between the front slide plate 216 and the rear slide plate 204 there ispositioned a pair of separable jaw members 218. The lower ends of thejaw members 218 embrace the lower end of the staple holding block 202.The front slide plate 216 is coupled, through a stud 220, to theaforementioned link 46. The staple holding block 202 is contoured toconform to the shape of the staple 193. The lower end of the stapleholding block 202 is undercut by an amount just sufficient to embracethe staple 193 as the slide member 188 of the staple forming subassembly82 pushes the staple forward. When the staple 193 is thus moved forwardand seated around the undercut shoulder of the block 202, the ends ofthe legs of the staple extend beyond the front edge of the block 202 asshown in phantom in Fig. 8. Spring biased guide clamps 219 carried bythe forward ends of the guide blocks 186 (Figs. 4 and 5) serve to guidethe ends of the staple 193 into proper position with respect to thestaple holding block 202.

As previously mentioned, the lower ends of the jaw members 218 embracethe end of the block 202. As may be seen in Fig. 12, this arrangementleaves a small horizontal opening through which each leg of the staple193 may protrude. The body of the staple is firmly held between theblock 202 and the jaws 218. In this condition, a cam 222 on the camshaft 10 causes the cam follower arm 36 to be moved in a direction tostart the link 26 in its downward motion through the associatedinterconnecting linkage. It will be recalled that a pin 48 extendsthrough the lower end of the link 26 and through the links 44 and 46 toa cam follower (not shown). The cam follower on the pin 48 engages afirst cam surface on the cam 50. The angle of the first cam surface issuch that it is substantially normal to a line drawn from that surfaceto the stud 206 which connects the link 44. to the rear slide plate 204.The initial downward motion of the link 26 then causes no correspondingmotion of the rear slide plate 204. However, substantially all of theinitial downward motion of the link 26 is transferred to the front slideplate 216 through the link 46 and its connecting stud 220. a

The rear surface of the front slide plate 216 is provided with a pair ofparallel channels 224 which are aligned with and are of a dimension toreceive the ends of the legs of the staple 193. In Fig. 8, it may beseen that the forward surface of the block 202 has a pair of guideprojections 226. These projections 226 also fit within the channels 224and serve to assure proper alignment of the front slide plate 216 withrespect to the staple.

As the front slide plate 216 is driven downward by the operation of thelink 26, the lower end thereof engages the extending legs of the staple,bending them downward over the edge of the embracing ends of the jawmembers 218 (see Fig. 13). Thus, the ends of the legs of the staple arebent at right angles to the main body or loop portion of the staple. Asthe front slideplate continues its downward motion, the bent legs of thestaple are enclosed in and supported by the channels 224 on three sidesand by the faces of the jaw members 218 on the. fourth side.

It will be noted that the lower ends of the jaw members 218 meet at theextreme ends, then taper away from each other to about the place wherethe wire of the staple 193 is engaged. There, a small horizontal step228 is formed. It is over this step 228 that the legs of the staple arebent downward. It will also be noted that the lower end of the frontslide plate 216 has bevelled corners. As the front slide plate 216continues its downward movement,

the bevelled corners engage a pair of pins.230 which protrude from thefront face of the jaw members 218. This engagement causes the jawmembers to be separated somewhat against the force of a spring 232 whichacts on a pair of studs 234 to normally biasthe two jaw members 218together.

As the jaw members 218 are separated, the steps 228 are moved out fromunder the legs of the staple 193, as shown in Fig. 14. At this point,the .cam follower on the pin 48 will have reached the end of the firstcam surface on the cam 50. The second surface on the cam 50 permits asmall simultaneous movement of both the front slide plate 216 and therear slide plate,204. This small movement places the lower end of thefront slide plate 216 and-the ends of the bent legs of the staple 193 inengagement with the surface of a sheet member 236 to which the staple isto be attached.

The link 26 then continues its downward movement. This continuedmovement brings the cam follower on the pin 48 into engagement with athird surface on the cam 50. This third surface is perpendicular to aline drawn from that surface to the center of the stud 220 on the frontslide member 216. Since the front slide member has reached the limit ofits downward movement, the continued movement of. the link 26 issubstantially all transferred to the rear slide plate 204. .This motionresults in a corresponding downward motion of the staple holding block202. The motion of the block 202 forces the ends of the staple throughthe sheet member 236. It will be remembered that the bent ends of thestaple legs were embraced by the closely fitting walls of the channels224. The open face of the channels 224 is closed by the tapered ends ofthe jaw members 218. Thus, the ends of the legs are completely supportedduring the initial descent of the block 202. Accordingly, considerablepressure may be applied to force the ends of the staple through thesheet member 236 without the likelihood of having the legs buckle. Thecomplete downward stroke of the block 202 firmly seats the loop or bodyportion of the staple in contact with the upper surface of the sheetmember 236 with the full length of the bent legs extending through andbelow the sheet, as shown in dotted lines in Fig. 14. When the staple isthus seated on the sheet member 236, the shoulders on the legs of thestaple will lie at the edge of the sheet.

Particular reference is now made to Figs. 6 and 15 to 18. Fig. 6 showssome of the details of the structure of the staple clinching subassembly52, certain of the parts having been broken away for clarity of detail.On a base guide block 238, there is positioned an upper guide block 240.Adjacent the guide block 240 may be seen the base block 183 whichcarries the anvil 108. The guide block 240 is provided with a centrallypositioned recess 242 which is contoured to match the contour of thestaple holding block 202 of the subassembly 22. A spring biased stapleejector 244 extends into the recess 242. A guide channel 246 in theblock 238'houses and guides a first clincher arm 248. The clincher arm248 moves in a vertical plane which makes an angle of about 45 withfront panel 2. It is operated by a bell crank 250 which is coupled tothe link 70. This link is connected through the previously described rod68 and associated crank 66 and link 64 to the carnfollower arm 62. A cam252 on the cam shaft drives the arm 62.

A guide channel 254 similar to the guide channel 246 but on the oppositeside of the block 240 from the channel 246 houses and guides a secondclincher arm 256 similar to the clincher arm 248 (see Fig. 4). Thissecond 8 clincher arm 256 is also coupled, through a bell crank 258, toits driving link 72.

The base guide block.238 has a recess 260 in its lower portion in whichis mounted a lever 262. The lever 262 is pivotally mounted on a bolt264. The forward end of the lever 262 carries a pair of frontleg-bending arms 266. The upper end of each of the leg-bending arms 266bears against a cam member 268. The other end of the lever 262 carries.a cam follower 270 which engages a cam surface on the end of the lever54. The lever 54, it will be recalled, is connected, through a link 58,to a cam follower arm 60. The arm 60 is, in turn, driven by a cam 272 onthe shaft 10. Directly coupled to the lever 54 adjacent to the camsurface thereon is a pair of rear legbending arms 274.

When the staple holding block 202 is moved downward, it fits snuglyintothe recess 242 in the upper guide block 240 and continues its downwardmotion until the staple 193 is held embraced on two sides by theundercut end of the block 202, on a third side by the walls of therecess 242 and on the fourth side by the upper surface of the block 238.With the body of the staple thus securely held, the cam 272 starts theforward end of the lever 54 in an upward motion. This motion isaccompanied by a corresponding upward motion of the front leg-bendingarms 266. However, the upward motion of the arms 266 is modified by thecam members 268 to introduce a rearward component to the motion of theupper ends of the arms 266. This motion is illustrated in Fig. 15 whereit may be seen that the arms 266 engage the depending legs of the staple193, bending those legs back on the main body of the staple alongstraight paths or lines and snugly against the lower surface of thesheet member 236, as shown in dotted lines in Fig. 15.

While the arms 266 are bending the legs of the staple backward, the rearleg-bending arms 274 are moved in position to become operative. Thecontinued motion of these arms 274, as shown in Fig. 16, causes the endsof the arms 274 to engage the now backwardly extending legs of thestaple 193. These legs are then bent upwardly over the edge of the sheetmember 236 and adjacent to the shoulders of the staple as shown indotted line in Fig. 16. As these arms are retracted, the clincher arms248 and 256 are moved toward the front, but at the aforementioned 45angle. A cam surface in the guide channels 246 and 254 first allows aninitial horizontal motion of the clincher arms, and then causes adownward component to be added to the motion. When these clincher armsmove in this manner, they extend into suitably provided slots 276 in thestaple holding block 202, carrying the ends of the legs of the stapleback over the shoulders in the staple and then downwardly to clinchthose ends into or against the upper surface of the sheet member 236.This movement is shown in Fig. 17 and results in a staple attachedsecurely to the edge of the sheet member 236 as shown in Fig. 18. Whenthe ends of the staple 193 have been clinched, the staple holding block202 moves upward, releasing the staple. The spring biased ejector 244pushes the staple out of the recess 242.

All of the foregoing steps and operations are carried out through thecooperative action of the several cams on the cam shaft 10 and theassociated cam followers. One revolution of the cam shaft 10, carryingthe several cams with it, is suflicient to carry out, in sequence, allof those steps and operations. In order to assure a reliable once-aroundor single revolution operation of the cam shaft 10, with proper indexingat the end of each revolution, there is provided a novel singlerevolution type clutch. This clutch is shown in Figs. 19, 20 and 21, andis also disclosed in my copending application, Ser. No. 525,534, filedAugust 1, 1955, for Apparatus for the Sensing and Registration ofSheets.

A flywheel 278 is coupled to a suitable motor (not 9 shown). A clutchdrum 280 is secured to the face of the flywheel 278 by suitable bolts282. The cam shaft 10 extends through the rear panel 6 and into coaxialalignment with the clutch drum 280. The end of the shaft 10 carries aclutch yoke 284. Pivotally secured to the yoke 284 at one end is a pairof clutch shoes 286 with suitable linings 288 thereon. The other end ofeach of the shoe members 286 is coupled to the opposite end of the yoke284 by an eccentric toggle arrangement which includes a pair of'togglelinks 290 eccentrically mounted on a toggle key 292. The toggle key 292is pivotally mounted on the yoke 284. The toggle ends of the two shoemembers286 are normally biased apart by a main clutch spring 294. Thespring 294 surrounds a guide pin 296 which extends through end portionson theshoe members 286. A pair of studs 298 extend out from the face ofthe yoke 284 and are positioned to limit the rotational movement of thetoggle key 292 by engagement with an arm 300 which extends from the hubof the toggle key. A spring 302 is coupled to the arm 300 of the togglekey 292 and biases that key in a I direction to augment the separatingforce applied to the shoes 286 by the spring 294.

The end of the yoke 284 adjacent to the toggle constitutes a cam surface304 which engages an indexing roller 306 carried by a spring biased arm308 positioned adjacent to the clutch. A clutch pin 310 extends throughthe rear panel 6 (see Figs. 4 and 21) and engages the arm 300 of thetoggle key 292. The pin 310 is retractable from engagement with the arm300 by operation of a lever 312 which is biased by a spring 314 andactuated by a solenoid motor 316.

In the idle condition, as shown in Fig. 19, the flywheel 278, with theclutch drum 280, is continuously rotated by the driving motor. Theclutch shoes 286 are held out of engagement with the drum 280 byoperation of the toggle arrangement. The arm 300 on the toggle key 292is held in position to cause disengagement of the shoes 286 by theclutch pin 310. With the clutch pin extended, as in Fig. 19, the arm 300of the toggle key is held securely between the clutch pin 310 and thelowermost of the studs 298. The clutch yoke 284 is prevented from movingin a reverse direction by the indexing roller 306 which engages the yoke284 adjacent the'cam' surface 304.

When the solenoid motor 316 is energized by operation of a suitableswitch (not shown), the lever 312 is operated to retract the clutch pin310. When the pm 310 is retracted, the arm 300 of the toggle key 292 ispulled by the spring 302 to shift the toggle bolts 290 and thus allowthe spring 294 to move the shoes 286 into driving engagement with thedrum 280. The upward movement of the arm 300, as viewed in Fig. 19, islimited by the uppermost one of the studs 298. When the shoes 286 aremoved into engagement with the drum 280, the yoke 284 is rotated,carrying the shaft 10 with it. By the time the yoke 284 nears thecompletion of one revolution, the pin 310 will have been returned to itsnormal or rest position. The arm 300 of the toggle key 292 thereuponcomes into contact with the side of the pin 310. The inertia of theclutch carries the mechanism with at least enough force to cause thecoaction of the arm 300 and the pin 310 to overcome the force of thespring 302 and the spring 294 to disengage the shoes 286 from the drum280. At about the same time that the arm 300 comes into contact with thepin 310, the roller 306 engages the cam surface 304 of the yoke 284. Asthe roller 306 moves outward on the cam surface, the spring bias on theroller arm 308 adds a further decelerating force to the yoke 284. Theposition of the roller 306 is made adjustable so that it drops over theedge of the cam surface 304 at the instant that the arm 300 is lockedbetween the pin 310 and the stud 298. This arrangement positively locksand indexes the yoke 284 and, hence, the cam shaft 10 a 0 in restposition, ready to start another cycle whenever the pin 310 isretracted.

There has thus been provided an improved apparatus for forming andapplying wire staples to the edge of a sheet member,the apparatus beingcharacterized in that no strains are imparted to the sheet member duringthe application, and being further characterized in an improved drivemeans for such apparatus which includes a selectively engageable andautomatically disengageable clutch mechanism.

I claim:

1. A wire staple fastener apparatus, comprising means for forming fromwire a reversely-bent staple having a loop portion and a pair of legs,means for holding said loop portion and bending the ends of said legs toa plane angularly related to said loop portion, means for confining saidlegs to maintain them relatively rigid and for driving said ends througha sheet member in proximity to an edge of said sheet member while saidlegs are so confined, means for thereafter'bending said leg ends backtoward said loop portion along straight paths snugly up against saidsheet member-and beyond said sheet member edge, and means for thereafterbending said leg ends -over said sheet member edge and over said legsand for clinching said ends onto the surface of said sheet member.

2. A wire staple fastener apparatus comprising means for forming fromwire a reversely-bent staple having a loop portion and a pair of legs,means for holding said loop portion and bending the ends of said legs toa plane at right angles to the plane of said loop portion, means forembracing and supporting said legs and for driving said ends through asheet member in proximity to an edge thereof, further means for holdingsaid loop portion and bending said leg ends back parallel to saidloopportion, and means for thereafter bending said leg ends over saidsheet member edge and over said legs and for clinching said ends ontothe surface of said sheet memher while said loop portion remains held bysaid last mentioned holding means.

3. A wire staple fastener apparatus comprising means for forming fromwire a substantially U-shaped staple having a loop portion and a pair oflegs, means for holding said loop portion and bending the ends of saidlegs to a plane perpendicular to the plane of said loop portion, meansfor embracing and supporting said bent ends of said legs and for drivingsaid ends through a sheet member in proximity to an edge thereof,further means for holding said loop portion during subsequent bendingoperations, means for bending said leg ends back parallel to said loopportion, means for thereafter bending said ends over said sheet memberedge and past said legs, and means for bending said ends over said legsand clinching said ends onto the surface of said sheet member.

4. A wire staple fastener apparatus comprising means for forming fromwire a substantially U-shaped staple having a loop portion and a pair oflegs, means for holding said loop portion and bending the ends of saidlegs to a plane perpendicular to the plane of said loop portion, meansfor embracing and supporting said bent ends of said legs and for drivingsaid ends through a sheet member in proximity to an edge thereof,further means for holding said loop portion during subsequent bendingoperations, means for bending said leg ends back parallel to said loopportion, means for there-after bending said ends over said sheet memberedge and past said legs, means for bending said ends over said legs andclinching said ends onto the surface of said sheet member, and means forejecting said staple from said last mentioned holding means.

5. A wire staple fastener apparatus comprising a staple forming assemblyfor forming from wire a reversely bent staple having "a loop portion anda pair of legs; a leg bending assembly including means for holding saidloop portion, means for bending the ends of said legs to a planeangularly related to the plane of said loop portion, and means fordriving said bent ends of said legs through a sheet member 'in proximityto an edge thereof, said driving means including means for embracing andsupporting said leg ends during said driving; and a leg end clinchingassembly including further means for holding said loop portion, meansfor bending said ends back toward said loop portion, means for furtherbending said ends over said sheet member edge, and means for stillfurther bending said ends over said legs and clinching said ends ontothe surface of said sheet member.

6. The invention as set forth inclaim characterized by the addition ofejection means for ejecting said loop from said last mentioned holdingmeans.

7. A wire staple fastener apparatus comprising a staple forming assemblyincluding a contoured anvil member and a complementary slide member forforming from wire a substantially U-shaped staple having a loop portionand a pair of legs; a leg bending assembly including means for holdingsaid loop portion, means for bending the ends of said legs to a planeperpendicular to the plane of said loop portion, and means for drivingsaid bent ends through a sheet member,'said driving means includingmeans for embracing and supporting said ends during said driving; a legend clinching assembly including further means for holding said loopportion, means for bending said ends back parallel to said loop portion,means for further bending said ends over the edge of said sheet memberand clinching said ends over said legs and onto the surface of saidsheet member; and common driving means for all of said assemblies.

8. A wire staple fastener apparatus comprising a staple forming assemblyincluding a contoured anvil and a com plementary slide member forforming from wire a substantially U-shaped staple having 'a loop portionand a pair of legs; a Wire feeding mechanism for feeding to said stapleforming assembly and severing a measured length of said wire; a legbending assembly including means for holding said loop portion, meansfor bending the ends of said legs to a plane perpendicular to the planeof said loop portion, and means for driving said ends through a sheetmember in proximity to an edge thereof, said driving means includingmeans for embracing and supporting said ends during said driving; a legend clinching assembly including further means for holding said loopportion, means for bending said ends back parallel to said loop portion,means for further bending said ends over said sheet member edge andclinching said ends over said legs and onto the surface of said sheetmember; and common driving means for all of said assemblies.

9. A wire staple fastener apparatus comprising a retractable stapleforming anvil contoured to the shape of the staple, a complementaryslide member, means for feeding and severing a measured length of wirebetween said anvil and said slide member, means for driving said slidemember into engagement with said anvil to form said wire into asubstantially U-shaped staple having a loop portion and a pair of legs,means for retracting said anvil from the path of said slide member,means for bending said legs of said staple to a plane perpendicular tothe plane of said loop portion, means for continuing the motion of saidslide member after formation of said staple to move said staple to saidleg bending means, said leg bending means including a staple holdingblock for supporting said loop portion of said staple, a pair ofseparable jaw members which embrace the end of said block and a portionof said loop portion, and a leg bending slide plate operable tobend theends of said legs over said jaw members and then to separate said jawmembers, said holding block being operable to drive said ends of saidlegs through a sheet member in proximity to an edge thereof, said slideplate having a pair of recesses for receiving and supporting said bentends of said legs during said driving, additional means including saidblock for holding said loop portion of said staple subsequent to thedriving of said leg ends through said sheet member, a first pair ofleg-bending arms operable to bend said leg ends back parallel to saidloop portion, a second pair of leg-bending arms operable to bend saidleg ends over said sheet member edge, and a pair of clincher armsoperable to bend said ends over said legs and clinch said ends onto thesurface of said sheet member.

References Cited in the file of this patent UNITED STATES PATENTS1,119,510 Heim Dec. 1, 1914 1,167,764 Liebig Jan. 11, 1916 1,264,901Craig May 7, 1918 1,811,028 Ryan June 23, 1931 1,825,140 Berthold Sept.29, 1931 2,138,495 Lewis Nov. 29, 1938 2,216,453 Paulin Oct. 1, 19402,566,031 Nilson Aug. 28, 1951

